perf: reuse compiler process when using sass-embedded

README.md

@@ -657,12 +657,12 @@ module.exports = {
 Type:
 
 ```ts
-type api = "legacy" | "modern";
+type api = "legacy" | "modern" | "modern-compiler";
 ```
 
 Default: `"legacy"`
 
-Allows you to switch between `legacy` and `modern` API. You can find more information [here](https://sass-lang.com/documentation/js-api).
+Allows you to switch between `legacy` and `modern` API. You can find more information [here](https://sass-lang.com/documentation/js-api). The `modern-compiler` option enables the modern API with support for [Shared Resources](https://github.com/sass/sass/blob/main/accepted/shared-resources.d.ts.md).
 
 > **Warning**
 >

src/index.js

@@ -47,7 +47,8 @@ async function loader(content) {
       : true;
 
   if (shouldUseWebpackImporter) {
-    const isModernAPI = options.api === "modern";
+    const isModernAPI =
+      options.api === "modern" || options.api === "modern-compiler";
 
     if (!isModernAPI) {
       const { includePaths } = sassOptions;
@@ -65,7 +66,7 @@ async function loader(content) {
   let compile;
 
   try {
-    compile = getCompileFn(implementation, options);
+    compile = getCompileFn(this, implementation, options);
   } catch (error) {
     callback(error);
     return;
@@ -74,7 +75,7 @@ async function loader(content) {
   let result;
 
   try {
-    result = await compile(sassOptions, options);
+    result = await compile(sassOptions);
   } catch (error) {
     // There are situations when the `file`/`span.url` property do not exist
     // Modern API

src/options.json

@@ -17,7 +17,7 @@
     "api": {
       "description": "Switch between old and modern API for `sass` (`Dart Sass`) and `Sass Embedded` implementations.",
       "link": "https://github.com/webpack-contrib/sass-loader#sassoptions",
-      "enum": ["legacy", "modern"]
+      "enum": ["legacy", "modern", "modern-compiler"]
     },
     "sassOptions": {
       "description": "Options for `node-sass` or `sass` (`Dart Sass`) implementation.",

src/utils.js

@@ -174,7 +174,8 @@ async function getSassOptions(
     };
   }
 
-  const isModernAPI = loaderOptions.api === "modern";
+  const isModernAPI =
+    loaderOptions.api === "modern" || loaderOptions.api === "modern-compiler";
   const { resourcePath } = loaderContext;
 
   if (isModernAPI) {
@@ -650,20 +651,21 @@ function getWebpackImporter(loaderContext, implementation, includePaths) {
 }
 
 let nodeSassJobQueue = null;
+const sassModernCompilers = {};
 
 /**
  * Verifies that the implementation and version of Sass is supported by this loader.
  *
+ * @param {Object} loaderContext
  * @param {Object} implementation
  * @param {Object} options
  * @returns {Function}
  */
-function getCompileFn(implementation, options) {
-  const isNewSass =
-    implementation.info.includes("dart-sass") ||
-    implementation.info.includes("sass-embedded");
+function getCompileFn(loaderContext, implementation, options) {
+  const isDartSass = implementation.info.includes("dart-sass");
+  const isSassEmbedded = implementation.info.includes("sass-embedded");
 
-  if (isNewSass) {
+  if (isDartSass || isSassEmbedded) {
     if (options.api === "modern") {
       return (sassOptions) => {
         const { data, ...rest } = sassOptions;
@@ -672,6 +674,32 @@ function getCompileFn(implementation, options) {
       };
     }
 
+    if (options.api === "modern-compiler") {
+      return async (sassOptions) => {
+        // eslint-disable-next-line no-underscore-dangle
+        const webpackCompiler = loaderContext._compiler;
+        const { data, ...rest } = sassOptions;
+
+        // Some people can run the loader in a multi-threading way;
+        // there is no webpack compiler object in such case.
+        if (webpackCompiler) {
+          const key = isDartSass ? "dart-sass" : "sass-embedded";
+          if (!sassModernCompilers[key]) {
+            // Create a long-running compiler process that can be reused
+            // for compiling individual files.
+            const compiler = await implementation.initAsyncCompiler();
+            webpackCompiler.hooks.shutdown.tap("sass-loader", () => {
+              compiler.dispose();
+            });
+            sassModernCompilers[key] = compiler;
+          }
+          return sassModernCompilers[key].compileStringAsync(data, rest);
+        }
+
+        return implementation.compileStringAsync(data, rest);
+      };
+    }
+
     return (sassOptions) =>
       new Promise((resolve, reject) => {
         implementation.render(sassOptions, (error, result) => {
@@ -686,7 +714,7 @@ function getCompileFn(implementation, options) {
       });
   }
 
-  if (options.api === "modern") {
+  if (options.api === "modern" || options.api === "modern-compiler") {
     throw new Error("Modern API is not supported for 'node-sass'");
   }